Apparatus for setting space heating systems into operation



Jan. 1, 1963 K. RAU 3,071,183

APPARATUS FOR SETTING SPACE HEATING SYSTEMS INTO OPERATION Filed July 15, 1960 3,071,183 APPARATUS FOR SETTING SPACE HEATEIG SYSTEMS INTQ OPERATION Kurt Ran, Tutzing, near Starnberg, Germany, assignor to Wilhelm Baler KG, Stockdorf, near Munich, Germany Filed July 13, 1960, Ser. No. 42,545 Claims priority, application Germany July 25, 1959 3 Claims. (Cl. 158-28) The invention relates to apparatus for setting space heating systems into operation, more especially systems, used in motor vehicles, comprising a burner for liquid fuels and an electrically-driven blower for the feed of combustion air to the burner. There are also usually provided in such heating devices an electrical ignition device to ignite the fuel-air mixture, a device to supervise the conditions of burning, and a switch by which the electrical drive device of the combustion air blower and the electrical ignition device are connectable to a source of electric current.

In a known form of such apparatus use is made of a press-button circuit for setting the device into operation, and upon depression of a button, designated for example Pro-glow, a glow plug is brought into service. Thereupon after illumination of an indicator lamp a second button is actuated, whereby the electrical drive device of the combustion air blower (which in most cases simultaneously drives a supply device for the fuel, and the heating medium), is brought into service.

This arrangement has the fundamental disadvantage that its actuation depends upon the undivided attention of the person operating it, and moreover necessitates two manual operations prior to the actual starting up, accompanied by observation of an indicator device to ascertain the condition of the glow plug.

A tendency has therefore already arisen to plan such a control apparatus to. include an automatic mechanism consisting of a time switch which, in the course of its running, automatically cuts out the ignition device after termination of the ignition period. However, apparatus of that kind suffers from the disadvantage that a mechanically-running clock must be provided, whereas in an automatic mechanism the aim is towards fully-electric control of the entire arrangement.

The aim of the present invention is to provide a mechanism with which it is possible to set the heating system in operation by depression of a single button. The apparatus according-to the invention is further intended to be equipped with as small a number as possible of switch contacts, but nevertheless to operate fully automatically, including, in cases of failure, control of the heating system.

According to the invention the switch, through which the electrical drive device of the combustion air blower and the electrical ignition device are connectable to a source of current, is equipped with a device for manual actuation and with a heating coil, which, upon a prearranged heating-up temperature being reached, cuts out the switch by means of a temperature-sensitive control element, e. g. a bimetallic spring.

A relay adapted to switch the electrical ignition device is preferably provided, in which case there branches off, between the switch contact of the relay and the connec tion of the electrical ignition device, a lead which runs to the heating coil of the switch which is adapted to be actuated by hand.

In order to obtain on the one hand a sufliciently long ignition period, and on the other hand the possibility of rapid cut-out by the heating coil, a resistance conveniently precedes the latter in circuit. A connecting lead of the heating coil, for example connected in parallel with the series resistance, may then be provided, in which is located a device for supervision of the burner temperature, which 3,071,183 Patented Jan. 1, 1963 ice normally interrupts this lead, and closes the same only upon the maximum permissible temperature of the burner being exceeded.

In an advantageous form of the invention the switch coil of the relay for the ignition device is connected in series with the device for the supervision of the conditions of burning.

The apparatus according to the invention may also be used in the case of burners which operate with an electromagnetically-controlled valve arranged in the fuel feed pipe of the burner, if the switch to be actuated by hand brings in the electromagnetic valve together with the drive device of the combustion air blower.

In the accompanying drawing a practical example of the apparatus according to the invention is shown in conjunction with a vehicle heating system, and from the following description thereof further advantages and features of the invention will be appreciated.

As may be seen from the drawing, an electric drive motor 2 located beside a heat transmitter 1 drives a blower 3 for air which is to be heated, and an enclosed blower 4, supplying the combustion air and the liquid fuel, which blower is connected by a pipe 5 to a burner 6 in which is mounted an ignition plug 7. A combustion chamber 8 is formed by the forward portion of a heating gas channel 9. The air to be warmed enters through an inlet aperture '10 into a heating air channel 11 which annularly encloses the heating gas channel 9, and passes from an outlet aperture 12 through a pipe (not shown) into the vehicle space to be heated.

Safety channels 13 and 14, which like other channels not visible in the drawing are formed with several ways running between the walls 15 and 16 parallel to the axis direction of the heat transmitter 1, are intended, in the case of a leaking heating gas channel 9, to prevent passage of the exhaust gases into the heating air channel 11, in which ribs 17, 18 are provided for better heat transmission.

When setting the above-described heating device into operation, contacts 21, 22 are closed by depression of a hand-actuating element 19 of a switch 24 The drive motor 2 is thereby connected to the positive terminal 23 of a source of electricity supply, such as a battery, and thus receives current. Likewise, by means of con nections 24 and 25 and a device 26 for supervision of the conditions of burning (which device, when a thermostat 27 is cold, closes contacts 28 and 29), a coil 30 of a relay 31 receives current, so that a relay switch 32 is closed, and thus the ignition plug 7 also receives current through the connection 33. By closure of the relay switch 32, however, current is also passed through a connection 34 and a resistance 35 to a heating coil 36 of the switch 20.

It ignition occurs, then within a short time the thermostat 27 of the device 26 for supervision of combustion warms up, and the contact 28 is thrown to the contact 37, hereupon a service lamp 38 lights, whilst the current to the relay coil 30 is interrupted, whereby the relay switch 32 opens. The ignition plug 7 and the heating coil 26 of the switch 20 are thus cut out.

If on the other hand no ignition occurs, then the thermost-at 27 remains cold and the contacts 28 and 29 remain closed. In this case the heating coil 36 of the switch 20 is excited and causes the heating up of a temperature-sensitive element 39, which is then displaced to the dotted position 39 and in doing so breaks the contacts 21 and 22, whereby the entire appliance is put out of operation.

If on the other hand, with contact 21 and 22 of the switch 29, and 28 and 29 of the device 26 closed, overheating of the appliance occurs, then contacts 40, 41 of a device 42 for supervision of the burner temperature are closed. The heating coil 36 thereby receives current directly through the connection 24 and the device 42, i.e. without interposition, of the series resistance, and in a very short time brings about the heating-up of the temperature-sensitive element 39 and thus, as previously described, the cutting-ou-t of the heating appliance.

The invention is not limited to use with a heating device of the above-described kind, but may also be used in the case of other heating devices, such for example as operate with a fuel pump and a combustion air blower separate therefrom. If for example the fuel is fed by gravity, a valve may be provided in the fuel pipe of the heating device and the valve may be controlled, together with the motor 2, by a magnetic coil connected in parallel to said motor. Variations and additions to the circuit may be made without departing from the scope of the invention, as defined in the appendant claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for setting space heating systems into operation, more especially in motor vehicles, including a burner for a mixture of liquid fuel and air; an electric motor; a blower for the feed of combustion air to said burner, driven by said electric motor; an electrical ignition device for ignition of the fuel-air mixture; a source of electric current; wiring providing a circuit for said ignition device and cur-rent source; a switch adapted to be actuated by hand through which said electric motor for driving the combustion air blower and the electric ignition device are connectable to said source of electric current, said switch being provided with a temperature-sensitive control element and a heating coil which, at a prearranged temperature, cuts out said switch by way of said temperature-sensitive control element, said heating coil being electrically connected to said source of electric current; wiring providing a circuit including said current source, switch, and motor, a resistance between the electric ignition device and the heating coil of the manually operable switch; a relay switch located in the circuit of the electric ignition device wherein said resistance is connected with one and the same end to said relay switch and to the electric ignition device; an overheat thermostat comprising a switch normally open, which is closed at a pre-arranged temperature, said switch, being connected in parallel with the circuit part formed by said resistance and said relay switch.

2. Apparatus for setting space heating systems into operation, more especially in motor vehicles, including a burner for liquid fuels; an electric motor; a blower for the feed of combustion air to said burner, driven by said electric motor; an electrical ignition device for igni tion of the fuel-air mixture; a source of electric current; a switch adapted to be actuated by hand through which said electric motor for driving the combustion air blower and the electric ignition device are connectable to said source of electric current, said switch being provided with a temperature-sensitive control element and a heating coil which, at a prearranged temperature, cuts out said switch by way of said temperature-sensitive control element; a relay switch located in the circuit of the electric ignition device and a lead running to the heating coil of the manually operable switch and being connected with the connecting lead between said relay switch and the electric ignition device; electrical circuit means for connecting said motor, said ignition device, and said heating coil to said electric current source; and combustion control means comprising a switch normally closed, but opened during operation of the burner, said switch being connected in series with the switching .coil of said relay switch.

3. Apparatus for setting space heating systems into operation, more especially in motor vehicles, including a burner for liquid fuels; an electric motor; a blower for the feed of combustion air to said burner, driven by said electric motor; an electrical ignition device for ignition of the fuel-air mixture; a source of electric current; wiring providing a circuit for said ignition device and current source; a switch adapted to be actuated by hand through which said electric motor for driving the combustion air blower and the electric ignition device are connecta-ble to said source of electric current, said switch being provided with a temperature-sensitive control element and a heating coil which, at a prearranged temperature, cuts out said switch by way of said temperature-sensitive control element, said heating coil being electrically connected to said source of electric current; wiring providing a circuit including said current source, switch, and motor, a resistance between the electric ignition device and the heating coil of the manually operable switch; a relay switch located in the circuit of the electric ignition device wherein said resistance is connected with one and the same end to said relay switch and to the electric ignition device; combustion control means comprising a switch normally closed, but opened during operation of the burner, said switch being connected in series with the switching coil of said relay switch; an overheat thermostat comprising a switch normally open, which is closed at a pre-arranged temperature, said switch being connected in parallel with the circuit part formed by said resistance and said relay switch.

References (lited in the file of this patent UNITED STATES PATENTS 

1. APPARATUS FOR SETTING SPACE HEATING SYSTEMS INTO OPERATION, MORE ESPECIALLY IN MOTOR VEHICLES, INCLUDING A BURNER FOR A MIXTURE OF LIQUID FUEL AND AIR; AN ELECTRIC MOTOR; A BLOWER FOR THE FEED OF COMBUSTION AIR TO SAID BURNER, DRIVEN BY SAID ELECTRIC MOTOR; AN ELECTRICAL IGNITION DEVICE FOR IGNITION OF THE FUEL-AIR MIXTURE; A SOURCE OF ELECTRIC CURRENT; WIRING PROVIDING A CIRCUIT FOR SAID IGNITION DEVICE AND CURRENT SOURCE; A SWITCH ADAPTED TO BE ACTUATED BY HAND THROUGH WHICH SAID ELECTRIC MOTOR FOR DRIVING THE COMBUSTION AIR BLOWER AND THE ELECTRIC IGNITION DEVICE ARE CONNECTABLE TO SAID SOURCE OF ELECTRIC CURRENT, SAID SWITCH BEING PROVIDED WITH A TEMPERATURE-SENSITIVE CONTROL ELEMENT AND A HEATING COIL WHICH, AT A PREARRANGED TEMPERATURE, CUTS OUT SAID SWITCH BY WAY OF SAID TEMPERATURE-SENSITIVE CONTROL ELEMENT, SAID HEATING COIL BEING ELECTRICALLY CONNECTED TO SAID SOURCE OF ELECTRIC CURRENT; WIRING PROVIDING A CIRCUIT INCLUDING SAID CURRENT SOURCE, SWITCH, AND MOTOR, A RESISTANCE BETWEEN THE ELECTRIC IGNITION DEVICE AND THE HEATING COIL OF THE MANUALLY OPERABLE SWITCH; A RELAY SWITCH LOCATED IN THE CIRCUIT OF THE ELECTRIC IGNITION DEVICE WHEREIN SAID RESISTANCE IS CONNECTED WITH ONE AND THE SAME END TO SAID RELAY SWITCH AND TO THE ELECTRIC IGNITION DEVICE; AN OVERHEAT THERMOSTAT COMPRISING A SWITCH NORMALLY OPEN, WHICH IS CLOSED AT A PRE-ARRANGED TEMPERATURE, SAID SWITCH, BEING CONNECTED IN PARALLEL WITH THE CIRCUIT PART FORMED BY SAID RESISTANCE AND SAID RELAY SWITCH. 